U.S. Pat. Publ. No. 2010/0056721 assigned to Kraton Polymers discloses a pentablock copolymer having a polyethylene end block, a styrene block polymer, a butadiene block polymer, a styrene block polymer and a polyethylene end block (PE-S-B-S-PE). This polymer is suitable for roto molding. The composition has high melt flow rate (MFR) and the block copolymer is not resistant to diesel fuel.
EP Pat. No. 1,474,458 assigned to Kraton Polymer discloses a styrene—styrene/butadiene—styrene (S-S/B-S) controlled distribution midblock polymer. For the purpose of defining “controlled distribution”, this patent is incorporated herein by reference.
A slush moldable composition is disclosed in U.S. Pat. Pub. No. 2012/0070665 assigned to Kraton Polymers. The block copolymer disclosed therein is preferably a triblock copolymer of styrene—styrene/ethylene butadiene—styrene (S-S/EB-S), wherein the midblock component EB is hydrogenated butadiene. The midblock is a controlled distribution of styrene and butadiene that are copolymerized, and then hydrogenated in a manner that primarily affects the butadiene. This block copolymer is not resistant to diesel fuel.
There is a need for a block copolymer composition that is diesel fuel resistant, and can be made by any melt processing technique such as injection molding, extrusion, rotational molding or slush molding, calendaring, or thermoforming techniques for the consumer applications such as, but not limited to, the automotive industry.